Lumber stacking apparatus

ABSTRACT

A lumber stacking apparatus is described for successively depositing layers of boards one on top of another to form a stack in which each board in a layer is horizontally spaced to enable the boards to be efficiently dried in a subsequent drying operation. The apparatus has a forked layer support means with projecting arms that receive and successively transport the layers over a stacking station and in front of a stripping means. The arms are lowered over the stack and then pulled back past the stripping means to strip the layer from the arms and onto the stack. The stripping means has an abutment surface that is inclined to shift the layer sideways as the arms are pulled back to space the boards as they are dropped from the arms.

United States-Patent 1 Lunden [45 JuneS, 1973 [541 LUMBER STACKINGAPPARATUS [75] Inventor: Sidney L. Lunden, Spokane, Wash.

[73] Assignee: Moore-lem, Inc., Spokane, Wash.

[22] Filed: Jan. 3, 1972 [21] Appl. No.: 214,725

Thedick ..214/6 DK Primary Examiner-Robert J. Spar Attorney-Greek Wells,Richard J. St. John andv David P. Roberts [57] ABSTRACT A lumberstacking apparatus is described for successively depositing layers ofboards one on top of another to form a stack in which each board in alayer is horizontally spaced to enable the boards to be efficientlydried in a subsequent drying operation. The apparatus has a forked layersupport means with projecting arms that receive and successivelytransport the layers over a stacking station and in front of a strippingmeans. The arms are lowered over the stack and then pulled back past thestripping means to strip the layer from the arms and onto the stack. Thestripping means has an abutment surface that is inclined to shift thelayer sideways as the arms are pulled back to space the boards as theyare dropped from the arms.

8 Claims, 1 1 Drawing Figures PATENTEDJUH 5 I975 SHEET 30F 6 OOP VQ'PATENIEDJuN 5 I973 SHEET 41]!" 6 PATENTEDJUH 5 I975 sum 50F 0 FIG 5 76H J 75 62 I so 63 I LUMBER STACKING APPARATUS BACKGROUND OF THEINVENTION This invention relates to lumber stacking apparatus and moreparticularly to lumber stacking apparatus capable of horizontallyspacing the boards as the boards are being stacked.

It is highly advantageous to space the boards both vertically andhorizontally in a stack to allow the boards to dry effectively.Generally stickers are placed transversely between each layer in a stackto separate the boards vertically. However, it has been very difficultto separate the boards horizontally. It has been very difficult toprovide a mechanism for separating the boards as the boards are beingplaced on the stack to provide horizontal spacing. During most stackingoperations a layer of boards is moved by an arm arrangement immediatelyover the stack and then withdrawn to one side stripping the boards offagainst a stripping abutment. To accomplish the stripping, the boardsmust necessarily be in abutting engagement with each other on the arms.In an attempt to overcome this, complicated and expensive drivemechanisms have been mounted on the arms for moving the boards off theend of the arms at a rate slightly slower than the arms are beingretracted.

One of the principal objects of this invention is to provide a lumberstacking apparatus having a very simple mechanism for stripping boardsoff an arm structure with the boards being deposited upon the stack atspaced intervals.

An additional object of this invention is to provide a lumber stackingapparatus that has a stripping means that is adjustable, enabling thespacing between the boards to be varied as desired.

A further object of this invention is to provide a lumber stackingapparatus having means for depositing the boards on a stack in ahorizontally spaced arrangement with very little modification toexisting stackers.

An additional object of this invention is to provide a lumber stackingapparatus that is relatively inexpensive to construct and very easy tomaintain.

A further object of this inventionis to provide a lumber stackingapparatus capable of horizontally spacing the boards as the boards aredeposited upon the stack that is considerably less expensive thanstacking equipment presently available.

These and other objects and advantages of this invention will becomeapparent upon reading of the following detailed description of apreferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of thisinvention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side view of a lumber stacking apparatus with a reciprocalcarriage mounted thereon for moving a forked layer support means to andfrom a stacking station; in which the lumber stacking apparatusincorporates the principal features of this invention with the carriagebeing shown in solid line at a fully retracted position and shown indotted line in a fully extended position;

FIG. 2 is a vertical side view similar to FIG. 1 except showing thecarriage during initial movement in solid line and approaching the fullyextended position in dotted line;

FIG. 3 is a plan view of the lumber stacking appara-' tus;

FIG. 4 is an isometric fragmentary view of a portion of the carriagestructure;

FIG. 5 is a vertical cross-sectional view taken along line 5-5 in FIG.3;

FIG. 6 is a vertical front view of the lumber stacking apparatus showingthe front of the stacking apparatus with the forked layer support partlylowered in front of a stripping mechanism;

FIGS. 7-9 are fragmentary illustration views showing the carriage beingsequentially retracted to pull an arm structure back past an abutmentsurface on a stripping mechanism to strip the boards off the forkedlayer support means to provide horizontal spacing between the individualboards;

FIG. 10 is an isolated fragmentary side view of a stripping memberillustrating its angular relation to the top surface of the forked layersupport means; and

FIG. 11 is an isolated fragmentary view of the stripping mechanism andmeans for sensing the height of the stack to raise the strippingmechanism after each layer is placed on the stack.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT front uprights 14. Theuprights are interconnected by longitudinal bracing l6 and transverse orcross-bracing 17. For purposes of illustration, the numerals 18-21 willidentify the front, rear, left side and right side respectively of thelumber stacking apparatus. The uprights 14 are spaced along the front18. The top of the framework provides a platform 25.

Individual boards are supplied one at a time to the lumber stackingapparatus from an infeed conveyor 27 having a plurality of parallellugged chains 28. The infeed conveyor 27 feeds the boards onto aplatform conveyor 30 that has an upper profile immediately above theplatform 25 for receiving the boards from the infeed conveyor 27 andconveying the boards onto a plurality of inclined longitudinal rollers32 that extend downward toward the front 18. The rollers 32 are inclinedforward with ends of the rollers supported by uprights 14. The gravityrollers 32 move the boards by gravity forward toward the front of themachine, Fixed abutments or stops 35 extend upward adjacent the forwardend of the gravity rollers 32 for projecting into the path of the boardson the gravity rollers to stop their forward movement and cause theboards to build up behind the stops 35 to form a course or layer.

Parallel upper-rails 36 extend longitudinally from the rear uprights 13to the front uprights 24 on the outside of upper longitudinal bracing 16(FIG. 9). Similar channel rails 37 are mounted along the bottom of theframework between the rear uprights l3 and the front uprights 14 on theinside of lower longitudinal bracing 16. A carriage 30 is reciprocallymounted on the lumber stacking apparatus for movement forward and backalong the rails 36 and 37. The carriage 38 has a general frame 40 withtransversely spaced longitudinal members 41 supporting rollers 42 whichride in the rails 36. The frame 40 has vertical members 44 that extendfrom the longitudinal members 41 downwardly supporting rollers 46 thatride in the rails 37. Cross braces 47 and 48 extend between the verticalmembers at vertically spaced positions.

The carriage 38 supports a forked layer support means generallydesignated with the numeral 50. The forked layer support means 50 ismounted for vertical movement on the carriage for picking up andsupporting a layer of boards thereon as the carriage moves forward. Theforked layer support means 50 includes a cross frame 52 having endroller frames 53 and 54 fixed thereto. Each of the roller frames 53 and54 has a diagonal frame member 56 (FIG. 4) that extends upward andrearward with a back roller 57 affixed to the upper end and a frontroller 50 fixed to the lower end for riding on respective front and rearsurfaces of a vertical frame member 44. Side rollers 60 are mounted onframe member 56 for riding on the outside surface of the verticalmembers 44.

The forked layer support means 50 has a plurality of longitudinallyextending arms 62 that are affixed to the cross frame 52 at arm bases63. The base 63 of each arm extends upward and forward at an inclinedangle with a longitudinal section 64 extending forward to an arm end 65.The longitudinal section 64 is progressively tapered having a topsurface 66 and a bottom surface 68 that are extended down to a thinblade at end 65 forming a wedge shape.

The forked layer support means 50 has a drive means which includes acounterweight 70 (FIG. 4) operatively connected thereto for biasing theforked layer support means 50 to an upper position.

The counterweight 70 is vertically movably mounted in uprightcounterweight channels 71 and 72 which are affixed to the cross braces47 and 48. Rollers 73 (FIG. 4) are mounted on the ends of counterweight70 for engaging the counterweight channels 71 and 72. The drive meanshas flexible chains 74 operatively interconnected between thecounterweight 70 and the forked layer support means 50 for biasing theforked layer support means upwardly. Each chain 74 extends over asprocket 75 affixed on a transverse shaft 76. The shaft 76 is rotatablymounted in pillow blocks 77 affixed to the counterweight channels 71 and72. Each chain 74 has an end 78 connected to the counterweight and anopposite end 80 that is connected to the back of the cross frame 52.Each chain end 80 operatively connected to the forked layer supportmeans 50 through a resilient housing connectors 02 (FIG. having a spring(not shown) therein. The counterweight 70 is designed in relation to theweight of the forked layer support means 50 to raise the forked layersupport to the elevated position when a layer of boards is removed fromthe arms. The counter-weight 70 is designed to allow the forked layersupport means 50 to descend when the arms are supporting a layer ofboards thereon.

The forked layer support means 50 also includes brackets 84 (FIG. 4)fixed to the cross frame 52 and extending downward with cam followers orrollers 85 mounted on the ends thereof.

The lumber stacking apparatus 10 further includes an accelerationregulating means for regulating the rate of descent and ascent of theforked layer support means 50. The acceleration regulating meansincludes a sprocket 87 affixed to the shaft 76. The sprocket 87 isoperatively connected to a motor (FIG. 5) through a continuous chain 88and a worm-gear reduction unit 91. The acceleration regulating means isdesigned to operate the reversible motor to cause the forked layersupport means 50 to move up and down at a uniform rate. The motor 90also acts as a brake means to stop further upward movement of the forkedlayer support means 50 when the layered support means reaches a desiredelevation and also stops the descent of the forked layer support means50 immediately adjacent the top of the stack. Should the layer supportmeans 50 engage an obstacle the chain portion between the sprocket 75and the resilient housing connector 82 will flex without breaking any ofthe equipment and without placing undue pressure on the obstacle.

The lumber stacking apparatus 10 includes a carriage drive 94 that isillustrated in FIGS. 1 and 2. The carriage drive 94 includes areversible motor 95 that is connected to a sprocket 97 by way oflacontinuous chain 96. Sprocket 97 is affixed to a pivot shaft 98. Foldingarm linkages 10,0 extend between the shaft 98 and the carriage formoving the carriage in response to the rotation of the shaft 98. Eachfolding arm linkage 100 includes an upper arm member 101 affixed to theshaft 98 that extends outwardly in a radial direction therefrom. Thefolding arm linkage 100 includes a forearm member 103 that is pivotallyconnected to the outer end of the upper arm member 101 and is also pivotally connected to the frame 40 of the carriage 38. The forearm member103 is formed in an arcuate mannet to enable the folding arm linkage 100to pass over center in a retracted position as shown in FIG. 1. Thepivotal connection between the outer end of the upper arm member 101 andforearm member 103 is referred to as the elbow pivot 104. One end of theforearm member 103 is pivotally connected to a bracket 105 (FIG. 4)affixed to the carriage frame 40 defining a pivot point 106.

The lumber stacking apparatus 10 also includes an arm tilting means 108(FIG. 4) that is operatively connected to the carriage drive 94 fortilting the ends 65 of the arms 62 upward to lift a layer of boards fromthe gravity rollers 32 and above the stops 35 and then for tilting thearms downward when the carriage is moved to the extended position withthe arms 62 extending over the stacking station. The arm tilting means108 includes the bracket 84 and the cam roller 85. The cam follower 85is engaged by a cam 110 that is formed on a pivot structure 111. Thestructure 111 (FIG. 4) is responsive to the angular movement of theforearm member 103 about the pivot point 106 for moving the cam 110against the cam follower 85 to cause the forked layer support means 50to pivot about the axis of the roller 57. The tilting of the arms isillustrated in FIG. 2. The pivot structure 111 includes an upstandingbracket 113 (FIG. 4) affixed to the carriage frame 40. The bracket 113pivotally supports a pivot lever 114 that has a forward end 115 and arear end 116. The cam 110 is formed on the forward end 115 having aninclined surface and a curved surface 121 that engages the cam follower05 as shown in FIGS. 2 and 4. The curvature of the curved surface 121 isrelatively constant to maintain the arm tilted upward during the majorportion of the movement of the carriage from the retracted position tothe forward extended position. Inclined surface 120 breaks away from thecurved surface 121 upward and rearward so that when the inclined surface120 moves along the cam follower 85 the arms are either being swungdownward or upward. A connecting arm lever 123 has one end pivotallyconnected to end 116 and one other end pivotally connected to a bracket125 that is affixed on the forearm member 124 spaced from the pivotpoint 106. The pivot structure 111 pivots about the bracket 113 inresponse to the angular movement of the forearm member 103 about thepivot point 106. The angular acceleration of the forearm member 103about the pivot point 106 varies considerably as the carriage is movedforward and back. The greatest angular acceleration occurs during theinitial movement of the carriage to and from the retracted position andduring the initial movement of the carriage to and from the extendedposition. As shown in FIG. 1 when the carriage (shown in solid lines) isin the retracted position the cam follower 85 rides on the upper portionof the inclined surface.l20. As the reversible motor 95 is operated itrotates the pivot shaft 98 to pivot the upper arm member 101 from theover center position downwardly in an are creating a rapid accelerationof the angular movement of the forearm member 103 about the pivot point106 to pivot the pivot structure 111 to move the cam 110 to engage thecam follower 85 with the inclined surface 120 to tilt or swing the arm62 upwardly within a very short movement forward of the carriage. As thecarriage continues forward, the cam follower 85 rides on the curvedsurface 121 to maintain the arms tilted up. As the carriage nears thefully extended position, the forearm member 103 is again moved in arapid angular acceleration to present the incline surface 120 to the camroller 85 to cause the arm to swing down in front of the upright members14. In the particular embodiment illustrated, the top surfaces 66 of thearms 62 are inclined downwardly when the arms are tilted to the downposition illustrated in FIG. 1. When the arms are tilted upward (FIG. 2)the top surfaces are in a substantially horizontal plane fortransporting a layer from the lumber stacking apparatus over thestacking station.

The lumber stacking apparatus has. a stripping means generallydesignated by the numeral 126 that includes a carriage 127 mounted forvertical movement immediately in front of the uprights 14. The outsidefront uprights 14 are constructed by channel beams to provide tracks forthe carriage 127. The carriage 127 has a cross frame member 128 withroller frames 130 .and 131 affixed to respective ends. Each of theroller frame members 130 and 131 have rollers thereon for rolling up anddown the outside uprights 14. The stripping means 126 includes aparallel guide means 133 (FIG. 6) that maintains the cross frame 128 ina substantially horizontal orientation as it is moved up and down. Theparallel guide means 133 includes a flexible cable 134 that has oneendfixed to a bracket 136 at an upper end of one of the uprights 14. Thecable 134 then extends downward from the bracket 136 passing under apulley 137 mounted in the cross member 128 and then horizontally throughthe cross member 128 and over a pulley 138. The other end of theflexible cable 134 extends downward and is connected to a bracket 140affixed to the lower end of the other front upright 14 as shown in FIG.6. The parallel guide means 133 maintains the carriage 127 in asubstantially horizontal condition as the carriage 127 moves up and downalong the uprights 14.

The stripping means 126 includes a plurality of stripping arms 142supported on the cross member by adjusting supports 143 (FIG. 10). Thearms 142 are transversely positioned between the arms 62. The strippingv arms 142 are mounted at an inclined vertical angle A (FIG. 10) to thehorizontal with the arms 142 extending forward and upward from the front18 of the machine. Each of the stripping arms 142 has an abutmentsurface 145 facing forward for engaging a side board of the layer onlayer support means 50 to strip the layer from the arms 62 as thecarriage 38 is retracted.

Specifically the lower end of the stripping arms 142 are pivotallyconnected to the adjusting support 143 by a bolt 147 (FIG. 10) providinga pivot point. A bolt 148 extends through the stripping arm spaced fromthe bolt 147 and through a curved slot 150 formed in the adjustingsupport 143. The angular inclination (angle A) of the arms may be variedby loosening the bolt 148 and sliding the bolt in the curved slot 150 toobtain the desired angular orientation to vary the spacing between theboards as they are stripped from the arms 62.

The stripping means 126 has a biasing means 152 for biasing the carriage127 upward to an upward position as shown in FIGS. 1 and 2. The biasingmeans includes flexible chains 153 and 154 (FIG. 6) that extend upwardover sprockets 155 and 156 respectively mounted on the uprights 14 andthen rearward over sprockets 157 and 158 affixed on a shaft 160 near therear of the machine (FIG. 3). Ends of the flexible chains 153 and 154extend downward and are connected to a counterweight 162 located nearthe rear of the machine (FIGS. 1, 2 and 3). The other ends of the chains153 and 154 are connected to the cross member 128. The counterweight 162has sufficient weight to bias the carriage 127 upward. The strippingmeans has drive means 164 and associated control means 166 forincrementally raising the stripping arms an increment corresponding tothe thickness of a layer (including sticker) of boards after each layeris placed on the stack.

The drive means 164 includes a sprocket 167 (FIG. 2 and 3) mounted onthe shaft 160. A chain 168 extends from the sprocket 167 to s sprocket170 operatively connected to the output shaft of a reversible motor 172.When the motor 172 is energized the shaft 160 is rotated to raise orlower carriage 127.

The control means 166 includes a sensing wheel assembly 174 mounted onthe cross frame member 128. The sensing wheel assembly 174 has an arm175 pivotably mounted to the bottom of the cross frame member 128 atpoint 176 (FIG. 11). The arm 175 extends upward behind the member 128and then forward and upward over the stack, A wheel 177 is mounted onthe forward end of arm for riding on the top layer of the stack. Afeeler switch 180 is mounted on the frame 128 bearing against the arm175. The switch 180 is operatively connected to the motor 172 to operatethe motor 172 when the switch 180 is actuated.

The apparatus 10 has means for sensing the height of the stack as thearms 62 are lowered in front of the lumber stacking apparatus to operatethe carriage drive 94 to retract the carriage 38 when the arms 62 arelocated immediately above the stack to strip the layer against theabutment surface 145 and deposit the boards at spaced intervals onto thestack. The sensing means includes a feeler switch 185 (FIGS. 1,7)mounted on the cross member 52.

During the operation of the lumber stacking apparatus the boards areindividually fed to the stacking apparatus by the feed conveyor 27. Theplatform conveyor 30 moves the boards from the rear of the machineforward onto the inclined gravity rollers 32. When the layer of boardsis formed on the gravity rollers behind the abutments 34 the carriagedrive 94 is operated to move the carriage forward. During the initialmovement of the carriage the forked layer support means 50 is operatedthrough the arm tilting means 108 to swing the arms 62 upward to liftthe layer from the gravity rollers 32 as shown in solid line in FIG. 2.Continual operation of the drive means 94 moves the lifted layer forwardpositioning the layer overlying the stacking station 11 and in front ofthe stripping means 126. As the carriage approaches the forward orextended position the arm tilting means 108 is operated to tilt the armsdownward as shown in FIG. 1 with the top surfaces 66 of the armsinclined downward and the bottom surfaces 68 substantially horizontal.

The reversible motor 90 is then operated to allow the forked layersupport means 50 to descend due to its weight in combination with theweight of the layer of boards on the arms. The forked layer supportmeans 50 moves downward to position the layer of boards in front of theabutment surface 145 immediately above the top layer of the stack, Therate of descent of the forked layer support means 50 is regulated by thespeed of the motor 90 through the worm gear reduction unit 91.

When the arms 62 descend to an elevation immediately above the stack asshown in FIG. 7, the feeler switch 185 engages the top layer of thestack deenergizing the motor 90 and energizing the carriage drive 94 toretract the carriage and pull the arms 62 back past the abutment surface145 with the top surface 66 of the arms intersecting the abutmentsurface 145 to strip the layer from the arms 62 and depositing the layeron the stack with the boards in the layer equally spaced form eachother. As the arms 62 are retracted, the board in the layer closest tothe side of the stack adjacent to the lumber stacking apparatus 10engages the abutment surface 145. As the arms continue to be withdrawn,the intersection of the top surface 66 with the abutment surface 145moves downwardly along the inclined abutment surface 145 as shown inFIGS. 7-9 to move the engaged side board along the abutment surface 145toward one side of the stack to progressively shift the supported layertoward the one side as the layer is being stripped from the arms. Theretraction of the arms causes the top surface 66 to move in relation tothe abutment surface 145 to cause the intersection of the two surfaces145 and 66 to move along the abutment surface 145 toward the one side.

For purposes of explanation the vertical angle between the abutmentsurface 145 and the horizontal is referred to as angle A. The anglebetween the abutment surface 145 and the top surface 66 is referred toas angle B. In this embodiment, angle B is greater than angle A toprovide spaced between the boards as they are deposited onto the stack.

Angle A may be varied by adjusting the inclination of the stripping arms142 as shown in FIG. 10. The angular adjustment provides for anadjustment in the spac ing between the boards as they are deposited uponthe stack.

After the arms 62 are fully retracted the motor is operated to allow thecounterweight 70 to raise the forked layer support means 50 to anelevated position with the layer support surface 66 immediately belowthe upper profile of the gravity rollers 32 in preparation toreceive asucceeding layer. Stickers can be placed either mechanically or manuallybetween each layer to vertically space the boards.

When the arm 62 begins to retract, the board closest to the uprights 14engages the wheel 177 and pushes the wheel 177 toward 'the uprights 14causing the arm 175 to pivot about point 176. As the arm 176 is pivoted,switch 180 is actuated. When the arms 62 are fully retracted, the motor172 is energized to rotate the shaft to raise the stripping assembly 127upward while the wheel 17'] maintains the engagement with the top of thestack as shown in FIG. 9 The upward movement continues until the arm ispivoted back to its original position and thereby de-actuates the switchwhich in turn stops the motor 178 (FIG. 11). In general terms thestripping assembly is indexed upward a distance corresponding to thethickness of a layer of boards plus a layer of stickers after a newlayer is added to reposition the stripping arms 142 for stripping a succeeding layer from the arms 62.

It should be understood that the above described embodiment is simplyillustrative of the principles of this invention and that numerous otherembodiments may be readily devised without deviating therefrom.Therefore, only the following claims are intended to define thisinvention.

What is claimed is:

1. In a lumber stacking apparatus for successively depositing layers ofboards one on top of another to form a stack, a board separating meansfor horizontally spacing the boards as they are deposited on the stack,comprising:

a layer support means having an inclined surface for receiving andsupporting a layer thereon, in which the layer support means ishorizontally movable for moving the layer support surface from a firstposition overlying the stack to a second position to one side of thestack;

a stripping means adjacent the one side of the stack having an inclinedabutment surface angularly oriented at a vertical angle to thehorizontal for projecting into the path of the layer supported on theinclined layer support surface as the layer support surface moves fromthe first position to the second position;

a drive means operatively connected to the layer support means formoving the layer support means in a horizontal plane from the firstposition to the second position to move the board supported on the layersupport means closest to the one side against the inclined abutmentsurface to strip the layer from the inclined support surface whilesimultaneously progressively moving said closest board along theinclined abutment surface toward the one side as the layer is beingstripped to progressively shift the layer horizontally toward the oneside to space each board as each board is deposited onto the stack.

2. In a lumber stacking apparatus as defined in claim I wherein thevertical inclined angle of the abutment surface is adjustable to varythe horizontal spacing between theboards.

3. In the lumber stacking apparatus as defined in claim 1 wherein thelayer support means includes wedge-shaped arms having an inclined topsurface defining the support surface.

4. 1n the layer stacking apparatus as defined in claim 3 wherein thestripping means includes stripping arms positioned between thewedge-shaped arms having an inclined surface facing the stack definingthe abutment surface in which the abutment surface is oriented at avertical angle in relation to the inclined support surface that isgreater than the vertical angle of the abutment surface to thehorizontal.

5. In the lumber stacking apparatus as defined in claim 4 wherein thestripping means has drive means for automatically incrementally raisingthe abutment surface after each layer of boards is placed on the stackin preparation for stripping a succeeding layer.

6. A lumber stacking apparatus for successively depositing layers ofboards one on top of another to form a stack, with boards beinghorizontally spaced, comprising:

a framework adjacent a side of the stack;

a forked layer support means'having extending arms in which the forkedlayer support means is horizontally movably mounted on said frameworkfor moving forward with the arms extending over the stack and for movingrearward in a horizontal plane with plane with the arms retracted, inwhich the arms have downwardly inclined support surfaces for receivingand supporting a layer of boards thereon;

a power drive means operatively connected to the forked layer supportmeans for selectively moving the forked layer support means forward andrearward over the stack;

a stripping means mounted on a framework adjacent to one side of thestack having abutment surface spaced between the arms and projectinginto the path of the layer supported on the inclined support surface asthe forked layer support means is moved rearward to strip the layer offthe support surface and onto the stack;

in which the abutment surface is oriented at an inclined vertical anglein relationship to the horizontal to cause the board closest to the sideof the stack to move horizontally as the layer is being stripped, toprogressively shift the layer horizontally toward the one side to spacethe boards as the boards are deposited upon the stack.

7. A lumber stacking apparatus as defined in claim 6 wherein thestripping means includes a cross frame carrying said abutment surfacethat is vertically movable adjacent to one side of the stack and whereinthe power drive means moves the arms over the cross frame when theforked layer support means is moved forward and wherein the forked layersupport means is also mounted for moving downward when the arms arefully extended and for moving upward when the arms are fully retractedand wherein the apparatus further comprises a drive means operativelyconnected to the forked layer support means for moving the extended armdownward to position the supported layer im rnediately above the stackin front of the abutment surface and for moving the retracted armsupward to receive a succeeding layer; anda control means responsive tothe lowering of the supported layer immediately above the stack toactivate the power drive means to retract the arms rearward past theabutment surfaces to strip the layer from the arms and onto the stack.

8. A lumber stacking apparatus as defined in claim 7 further comprising:

board stops mounted on the framework adjacent the side of the stack;

inclined gravity rollers mounted on the framework for conveying boardsby gravity toward the stops to form a layer on the framework;

feed meansfor successively feeding boards onto the gravity roller; and

means responsive to the movement of the forked layer support means fortilting the arms upward above the gravity rollers as the forked layersupport means is moved forward to pick up a layer from the gravityrollers and raise the supported layer above the stops and carrying thesupported layer forward over the stack and in front of the stops.

1. In a lumber stacking apparatus for successively depositing layers ofboards one on top of another to form a stack, a board separating meansfor horizontally spacing the boards as they are deposited on the stack,comprising: a layer support means having an inclined surface forreceiving and supporting a layer thereon, in which the layer supportmeans is horizontally movable for moving the layer support surface froma first position overlying the stack to a second position to one side ofthe stack; a stripping means adjacent the one side of the stack havingan inclined abutment surface angularly oriented at a vertical angle tothe horizontal for projecting into the path of the layer supported onthe inclined layer support surface as the layer support surface movesfrom the first position to the second position; a drive meansoperatively connected to the layer support means for moving the layersupport means in a horizontal plane from the first position to thesecond position to move the board supported on the layer support meansclosest to the one side against the inclined abutment surface to stripthe layer from the inclined support surface while simultaneouslyprogressively moving said closest boArd along the inclined abutmentsurface toward the one side as the layer is being stripped toprogressively shift the layer horizontally toward the one side to spaceeach board as each board is deposited onto the stack.
 2. In a lumberstacking apparatus as defined in claim 1 wherein the vertical inclinedangle of the abutment surface is adjustable to vary the horizontalspacing between the boards.
 3. In the lumber stacking apparatus asdefined in claim 1 wherein the layer support means includes wedge-shapedarms having an inclined top surface defining the support surface.
 4. Inthe layer stacking apparatus as defined in claim 3 wherein the strippingmeans includes stripping arms positioned between the wedge-shaped armshaving an inclined surface facing the stack defining the abutmentsurface in which the abutment surface is oriented at a vertical angle inrelation to the inclined support surface that is greater than thevertical angle of the abutment surface to the horizontal.
 5. In thelumber stacking apparatus as defined in claim 4 wherein the strippingmeans has drive means for automatically incrementally raising theabutment surface after each layer of boards is placed on the stack inpreparation for stripping a succeeding layer.
 6. A lumber stackingapparatus for successively depositing layers of boards one on top ofanother to form a stack, with boards being horizontally spaced,comprising: a framework adjacent a side of the stack; a forked layersupport means having extending arms in which the forked layer supportmeans is horizontally movably mounted on said framework for movingforward with the arms extending over the stack and for moving rearwardin a horizontal plane with plane with the arms retracted, in which thearms have downwardly inclined support surfaces for receiving andsupporting a layer of boards thereon; a power drive means operativelyconnected to the forked layer support means for selectively moving theforked layer support means forward and rearward over the stack; astripping means mounted on a framework adjacent to one side of the stackhaving abutment surface spaced between the arms and projecting into thepath of the layer supported on the inclined support surface as theforked layer support means is moved rearward to strip the layer off thesupport surface and onto the stack; in which the abutment surface isoriented at an inclined vertical angle in relationship to the horizontalto cause the board closest to the side of the stack to move horizontallyas the layer is being stripped, to progressively shift the layerhorizontally toward the one side to space the boards as the boards aredeposited upon the stack.
 7. A lumber stacking apparatus as defined inclaim 6 wherein the stripping means includes a cross frame carrying saidabutment surface that is vertically movable adjacent to one side of thestack and wherein the power drive means moves the arms over the crossframe when the forked layer support means is moved forward and whereinthe forked layer support means is also mounted for moving downward whenthe arms are fully extended and for moving upward when the arms arefully retracted and wherein the apparatus further comprises a drivemeans operatively connected to the forked layer support means for movingthe extended arm downward to position the supported layer immediatelyabove the stack in front of the abutment surface and for moving theretracted arms upward to receive a succeeding layer; and a control meansresponsive to the lowering of the supported layer immediately above thestack to activate the power drive means to retract the arms rearwardpast the abutment surfaces to strip the layer from the arms and onto thestack.
 8. A lumber stacking apparatus as defined in claim 7 furthercomprising: board stops mounted on the framework adjacent the side ofthe stack; inclined gravity rollers mounted on the framework forconveying boards by gravity toward the stops to form a layer on thEframework; feed means for successively feeding boards onto the gravityroller; and means responsive to the movement of the forked layer supportmeans for tilting the arms upward above the gravity rollers as theforked layer support means is moved forward to pick up a layer from thegravity rollers and raise the supported layer above the stops andcarrying the supported layer forward over the stack and in front of thestops.